Regarding restrictions we can say that if they upgrade to IOS 4.1 on the iPhone 3G / 4 with no different to the original mobile provider will lose the ability to make calls, you can not unlock the baseband.

Note:Because GeoHot no Mac program, the hacker Wizdazhas helped to write this version of Limera1n

The tutorial Limera1n to jailbreak with the iPhone/ iPod Touch / IPAD is similar to Windows!